package example;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import sun.applet.Main;
 
public class sha1example {
 
    private static String convertToHex(byte[] data) {
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < data.length; i++) {
            int halfbyte = (data[i] >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                if ((0 <= halfbyte) && (halfbyte <= 9))
                    buf.append((char) ('0' + halfbyte));
                else
                    buf.append((char) ('a' + (halfbyte - 10)));
                halfbyte = data[i] & 0x0F;
            } while(two_halfs++ < 1);
        }
        return buf.toString();
    }
 
    public static String SHA1(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException  {
	    MessageDigest md;
	    md = MessageDigest.getInstance("SHA-1");
	    byte[] sha1hash = new byte[40];
	    md.update(text.getBytes("iso-8859-1"), 0, text.length());
	    sha1hash = md.digest();
	    return convertToHex(sha1hash);
    }
    
    public static void main(String[] args)  {
    	try {
			System.out.println( SHA1("asd") + " --> length: " + SHA1("asd").length() );
		} catch (NoSuchAlgorithmException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
    }
}
